BIO RAD VERSADOC, Руководство пользователя

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User’s Manual 4-
5
Zoom Lens 50 mm Fixed focal length lens
FIGURE 4.4
4.3.5 Aperture Adjustment
The aperture or f-stop ring is located at the top of the lens (Figure 4.4) and controls the
amount of light that passes through the lens to be captured by the CCD camera. When the
aperture is fully open, the f-stop number will be smallest, the depth of field will be the lowest
and the most light will pass through the lens. When the aperture is fully closed, the f-stop
number will be largest, the depth of field will be highest and the least light will pass through
the lens. For low signal applications such as chemiluminescence, it is recommended that
the aperture be fully opened to the smallest f-stop value.
Note: When the aperture on the zoom lens is fully closed (largest f-stop setting of 22), the aperture ring
locks. To unlock the aperture ring push the black release button to the right of the f-stop indicator while
turning the ring to the right (counter-clockwise).
Note: The aperture ring on the 50 mm lens will not lock in the fully closed (f-stop 16) position, unless the
user activates the lock mechanism on the lower right hand side of the f-stop indicators. To lock in this
position move the button (white dot) up so that it aligns with the orange indicator. It is not recommended
that the lens be locked in this position for chemiluminescence experiments as this setting allows the least
light through the lens.
4.3.6 Zoom Adjustment
When using the zoom lens the view area of the image can be adjusted by rotating the zoom
ring (Figure 4.4). The zoom ring is located directly below the aperture ring. At maximum
zoom the indicator on the lens will be set to its highest specified focal length 40 or 80 mm
depending on which lens is being used, also the image resolution will be at its best.
The zoom setting can be adjusted and viewed in real time by selecting the POSITION
function in the VersaDoc acquisition window. The image display window will now show a
real-time image of the sample, as it will be captured. This image refreshes every second to
help you optimize your zoom settings.
Note: The 50 mm lens offers no zoom adjustment.
Zoom
Ring
Aperture
Ring
Focus
Ring